| Abbreviation | Definition |
|---|---|
| ATE | Append To End |
| ATI | Activist Times Inc |
| ATISS | Advanced Technology & Intelligent Systems Solutions |
| ATL | Active Template Library |
| ATL | Automatic Tape Library |
| ATM | Adobe Type Manager |
| ATM | Aschronous Transfer Mode |
| ATM | Automated Transactional Management |
| ATMP | Ascend Tunnel Management Protocol |
| ATP | All Tests Passed |
| ATR | Andy's Techno Rules |
| ATSF | Alert Transport Service Facility |
| AUA | Acceptable Use Agreement |
| AUBA | Asociacion de Usuarios de Borland Argentina |
| AUBP | Average Utilization of Batch Processors |
| AUGI | Autodesk Users Group International |
| AUI | Access Unit Interface |
| AUI | Adaptable User Interface |
| AUI | Application User Interface |
| AUI | Attachment Unit Interface |